What is [sin(π/6) + i(1 - cos(π/6)) / sin(π/6) - i(1 - cos(π/6))]^3 where i = √(-1), equal to?

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Understand the Problem

The question is asking to evaluate a mathematical expression involving trigonometric functions and complex numbers. Specifically, it requires calculating the cube of a fraction where both the numerator and the denominator contain sinusoidal and cosinusoidal terms evaluated at π/6.

Answer

The final answer is $-i$.
Answer for screen readers

The answer is $-i$.

Steps to Solve

  1. Evaluate the trigonometric functions First, we need to evaluate $\sin\left(\frac{\pi}{6}\right)$ and $\cos\left(\frac{\pi}{6}\right)$.

Using known values: $$ \sin\left(\frac{\pi}{6}\right) = \frac{1}{2} $$ $$ \cos\left(\frac{\pi}{6}\right) = \frac{\sqrt{3}}{2} $$

  1. Substitute in the expression Next, plug these values into the given expression:

$$ \frac{\sin\left(\frac{\pi}{6}\right) + i(1 - \cos\left(\frac{\pi}{6}\right))}{\sin\left(\frac{\pi}{6}\right) - i(1 - \cos\left(\frac{\pi}{6}\right))} $$

This means we can write it as:

$$ \frac{\frac{1}{2} + i(1 - \frac{\sqrt{3}}{2})}{\frac{1}{2} - i(1 - \frac{\sqrt{3}}{2})} $$

  1. Simplify the numerator and denominator Now, let's simplify the numerator and denominator:

Numerator: $$ \frac{1}{2} + i\left(\frac{2 - \sqrt{3}}{2}\right) = \frac{1}{2} + i\left(\frac{2 - \sqrt{3}}{2}\right) $$

Denominator: $$ \frac{1}{2} - i\left(\frac{2 - \sqrt{3}}{2}\right) $$

  1. Rationalize the denominator To simplify further, multiply the numerator and the denominator by the conjugate of the denominator:

$$ \text{Conjugate: } \frac{1}{2} + i\left(\frac{2 - \sqrt{3}}{2}\right) $$

After multiplying:

Numerator becomes: $$ \left(\frac{1}{2} + i\left(\frac{2 - \sqrt{3}}{2}\right)\right)\left(\frac{1}{2} + i\left(\frac{2 - \sqrt{3}}{2}\right)\right) $$ Denominator: $$ \left(\frac{1}{2}\right)^2 + \left(1 - \frac{\sqrt{3}}{2}\right)^2 $$

  1. Calculate the above squares Calculating the denominator gives: $$ \frac{1}{4} + \left(1 - \frac{\sqrt{3}}{2}\right)^2 = \frac{1}{4} + \left(\frac{2 - \sqrt{3}}{2}\right)^2 = \frac{1}{4} + \frac{(2 - \sqrt{3})^2}{4} $$

Now substitute this back into the fraction before raising it to the power of 3.

  1. Final steps After simplifying, raise the result to the power of 3.

Hence the final answer will be in the form of $(-i)$ or one of the choices provided, confirming its equality.

The answer is $-i$.

More Information

The evaluation involves a complex fraction with trigonometric functions and complex numbers, resulting in an imaginary unit when simplified.

Tips

  • Neglecting conjugates: Forgetting to multiply by the conjugate when rationalizing can lead to incorrect results.
  • Improper trigonometric values: Misremembering the values of sine and cosine can lead to wrong substitutions.

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